1. Field of the Invention
The present invention relates in general to computers, and, more particularly, to an apparatus and method of hierarchical enclosure management services.
2. Description of the Prior Art
Data storage systems are used to store information provided by one or more host computer systems. Such data storage systems receive requests to write information to a plurality of data storage devices and requests to retrieve information from that plurality of data storage devices. It is known in the art to configure the plurality of data storage devices into two or more storage arrays.
Storage Enclosures, e.g., disk enclosures in a “Just-A-Bunch-Of-Disks” topology (JBODs), “Switched-Bunch-Of-Disks” topology (SBODs), and the like have traditionally been implemented with a single set of physical resources. The devices are generally treated as a single instance of an enclosure with all shared resources controlled by a common single enclosure services process/instance. Most vendor components to manage storage enclosures have been developed with consideration to the number of hard disk drive (HDD) devices that will be within a single enclosure package and most original equipment manufacturer (OEM) storage enclosure implementations have a legacy of products that conform to this convention.
To improve the storage density [number of HDDs packaged per Electronics Industry Association (EIA)-sized unit in a single storage enclosure], high density packaging techniques can be used to increase the number of HDDs within a given volume of space. In addition, each individual instance of a storage enclosure is typically interconnected via a disk fabric interconnect technology [e.g., Fibre Channel Arbitrated Loop (FC-AL), Serial Attached SCSI (SAS), SCSI, SATA, SSA] at some cost of interconnect componentry [cables, small form factor pluggable transceiver modules, gigabit interface controllers (GBICs)].
Additionally, many storage controller systems provide multiple disk controller instances to allow users to partition their storage devices into separate domains for reasons of reliability, availability, and serviceability. Once the number of HDDs moves beyond the number that traditional enclosures and enclosure management components are designed for, new components and new storage enclosure configurations must be designed to meet the demand for increased HDD density. As such, new development of enclosure management services software and HDD communication fabric management code is required to be developed at significant design, development, and verification expense.